Seagram liquor heiress Clare Bronfman pleaded guilty on Friday to harboring an illegal immigrant and enabling credit card fraud as part of an alleged sex cult based in upstate New York.

Bronfman, 40, entered her plea to the two criminal counts before US district judge Nicholas Garaufis in federal court in Brooklyn, New York. She is one of several people charged in connection with a secretive organisation called Nxivm, which federal prosecutors have described as a racketeering organisation.

Bronfman admitted that she knowingly harboured a woman brought to the US on a fake work visa in order to obtain that woman’s labour for herself and the organisation. She also said she helped Nxivm’s founder, Keith Raniere, use a deceased woman’s credit card.

As part of her plea, Bronfman agreed to forfeit $6 million, and not to appeal any prison sentence of 27 months or less. She said she was “truly remorseful”.

“I wanted to do good in the world and help people,” she said. “However, I have made mistakes.” Bronfman’s lawyer, Mark Geragos, said after the hearing that his client did not have an agreement to cooperate with prosecutors.

Actress Allison Mack, best known for her role on the WB television show “Smallville,” pleaded guilty earlier this month to blackmailing two women in connection with Nxivm. Former Nxivm president Nancy Salzman and her daughter Lauren Salzman pleaded guilty in March.

Another Nxivm member, Kathy Russell, also pleaded guilty on Friday to falsifying a visa application for another person associated with Nxivm, leaving Raniere as the sole defendant in a trial expected to begin next week.

Raniere, 58, was arrested on sex trafficking charges in March 2018, and is being held without bail. Prosecutors accused Raniere of running a cult-like secret society within Nxivm in which women were branded with his initials and forced to have sex with him. Last month, prosecutors unsealed new charges accusing Raniere of sexually exploiting a minor.